Faeces prove American natives were cannibals

Scientists have found the first unequivocal evidence that some human societies engaged in cannibalism, a practice that has long been the subject of debate among anthropologists.

Scientists have found the first unequivocal evidence that some human societies engaged in cannibalism, a practice that has long been the subject of debate among anthropologists.

An analysis of a 900-year-old desiccated faeces has revealed that it contains a protein found only in the human heart and muscles. The scientists conclude that the person must have eaten human flesh.

Although there are many anecdotal accounts of people engaging in "customary cannibalism" on a social scale - as opposed to solitary criminals or desperate survivors of a catastrophe - some anthropologists have dismissed the reports as fictional embellishments of rumours circulated by enemy tribes bearing a grudge.

The sceptics have also dismissed evidence of cut marks on human bones that resemble the same knife marks made on animals butchered for their meat, saying that other interpretations are just as likely.

The matter seems to be settled in a report published today in the journal Nature by Richard Marler and his colleagues at the University of Colorado School of Medicine in Denver, who made the faecal analysis from a "coprolite", or turd, found at a Puebloan indian site from around AD1150.

"For many years, there has been a debate over whether cannibalism occurred in the American south-west. This is the final piece of evidence that demonstrates that people consumed other humans," Dr Marler said. The cannibalism could have been ritual or an act of "terrorism" by competing tribes, he said.

The research was based on a sensitive test for human myoglobin, an oxygen-carrying protein found only in the heart or the muscles connected to the skeleton. It does not occur in the "smooth" muscle of the intestine so could not have entered the faeces through bleeding or illness, Dr Marler said.

A cooking pot from the site also had human myoglobin present, indicating that human flesh was prepared in it. And the site contained the butchered bones of seven individuals, men, women and children.

The human coprolite was found in the ashes of a hearth. The faeces was unburnt and had lain undisturbed for nearly nine centuries.

"Every society in the world has had some cannibalism," Dr Marler said. "This site was not about the consumption of loved ones. There was a lot of violence there and they did not bury the bones afterwards."